Q: If the coefficient of mutual induction of the primary and secondary coils of an induction coil is 6H and a current of 5A is cut off in 1/5000 second, calculate the emf induced in the secondary coil.
Sol: $\large |e| = M\frac{dI}{dt}$
$\large |e| = 6 \times \frac{5}{1/5000}$
= 15 × 104 V